Titanium plasma coated medical grade thermoplastic or polymer proximal and distal interphalangeal toe implant

ABSTRACT

A medical grade thermoplastic or polymer implant with an osteoconductive coating is provided, specifically for corrections of the distal and proximal interphalangeal toe joints of the foot. The implant can be either straight or angled, and can be either solid or cannulated for insertion. The implant is sized and shaped depending on the specific anatomy and desired correction. End portions of the implant may be coated with an osteoconductive coating that promotes bone growth, but may reduce radiolucency. Thus, a central portion of the implant may remain uncoated to increase radiolucency of the implant at the region where two bones come together.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of U.S. Ser. No. 15/785,339,filed Oct. 16, 2017, now U.S. Pat. No. 10,470,890, which is acontinuation-in-part of U.S. application Ser. No. 14/825,082, filed onAug. 12, 2015, which claims the benefit of U.S. Provisional ApplicationNo. 62/284,398, to which U.S. Design Application No. 29/474,342, filedAug. 12, 2014 (the '342 application), was converted in accordance withthe Request for Conversion to a Provisional Application under 37 C.F.R.1.53(c)(2) filed Apr. 22, 2015, in the '342 application, which wasgranted on Aug. 17, 2015. All of the foregoing applications are herebyincorporated by reference herein in their entireties.

FIELD

This present disclosure relates generally to medical implants and, moreparticularly, to orthopedic and podiatry implants for use in a jointfusion (including fibrous union or even non-union) of the proximal ordistal interphalangeal (PIP or DIP, respectively) joint of the toes. Thepresent disclosure also relates to an interphalangeal fusion implantwhich provides for a stable relationship between the two phalanges, suchas the proximal phalange and the intermediate phalange, which exists atthe proximal interphalangeal joint.

BACKGROUND

Hammer toe is a deformity of the toe that affects the alignment of thebones adjacent to the proximal interphalangeal (PIP) joint or distalinterphalangaeal (DIP) joint. Digital deformities of the fingers andtoes are some of the most common conditions encountered by extremityspecialists. These digital deformities can cause pain and lead todifficulty in walking, grasping or holding items and even wearing shoes.Examples of such deformities are popularly known as mallet finger,jersey finger, hammertoe, claw toe and mallet toe, as well as manyothers, indicative of several different pathologies.

Depending on the severity of the deformity, surgery may be required tocorrect the deformity by fusing one or both of the joints together,including the proximal interphalangeal (PIP) joint and the distalinterphalangeal (DIP) joint. In order to prevent recurrence of thedeformity and ensure the success of the surgical procedure, a proximalinterphalangeal (PIP) joint or distal interphalangeal (DIP) jointarthrodesis is typically performed. The most commonly used hammertoeprocedure is that which was described by Post in 1895 and is referred totoday as the Post Arthroplasty or Post Procedure. It involves resecting(removing) the knuckle of the toe at the level of the proximalinterphalangeal joint (PIPJ). This joint is the joint closest to thepoint where the toe attaches to the foot. Typically the Post Procedurewill be performed in conjunction with a tendon release on the top(extensor surface) of the foot. The combination of these two proceduresresults in a toe that will lay flat avoiding direct pressure from theshoe. In the case of a mallet toe or claw toe, the Post Procedure may beperformed with or without the tendon lengthening. The PIPJ is alignedwith the rest of the toe in a corrected anatomical position andmaintained in place by the use of a 0.045 or 0.062 inch diameterKirschner wire (K-wire) driven across the joint. Initially, the K-wireis placed from the PIPJ through the tip or end of the toe. It is thendriven in retrograde fashion into the proximal phalanx. The exposedK-wire is bent to an angle greater than 90 degrees, and the bent portionwhich is external of the body is cut. Normally a plastic or polymericball is placed over the exposed end of the K-wire to protect thepatient. The K-wire normally remains in the foot of the patient untilthe PIP and/or DIP joints are fused in approximately 6 to 12 weeks. Thisconventional treatment has several drawbacks such as preventing thepatient from wearing closed shoes while the K-wire is in place, and theplastic or polymeric ball may snag on some object due to it extendingfrom the tip of the toe resulting in substantial pain for the patient.

There is a fairly high incidence of malunion (healing crooked) withtraditional K-wire fixation. Other possible drawbacks of K-wire reportedin the literature is that it must be removed which may cause additionalpain for the patient along with the reported concern of infection at theinsertion point of the toe.

Yet other conventional implants, in lieu of a K-wire, include threadedscrews that are disposed within the adjacent bones of a patient's footor nitinol implants that expand due to the rising temperature of theimplant to provide outward forces on the surrounding bone wheninstalled. However, the temperature sensitive material of a nitinolimplant may result in the implant deploying or expanding prior to beinginstalled, which requires a new implant to be used. Recently, PEEKpolymer implants have been used to accomplish the same fixation of thedeformity but these implants do not create bone ingrowth or upgrowth onthe implant, which may lead to rotation of the implant and notaccomplish the fusion required to correct the deformity over time forthe patient. Accordingly, an improved implant for treating toedeformities is desirable.

SUMMARY

In one or more embodiments, an interphalangeal toe implant for deformitycorrection of a hammer toe, a mallet toe, a claw toe, or an arthritictoe condition comprises an implant body. The implant body can have athreaded proximal end section for fixation to a first bone portion, anda distal end section with fixation features for fixing the implant bodyto a second bone portion. The implant body can comprisepolyetheretherketone (PEEK) and can have an osteoconductive coating thatcan comprise titanium plasma and/or hydroxyapatite (Harp). Theosteoconductive coating can provide a surface for promoting bone growthwhen the implant is implanted in the first and second bone portions. Theimplant body can be substantially radiolucent such that edges of the twofused bones can be viewed under fluoroscopy even when the implant isfully implanted.

In one or more embodiments, an interphalangeal toe implant forcorrection of a deformity of the toe comprises an implant body. Theimplant body can have a threaded proximal end section for fixation to afirst bone portion, and a distal end section with fixation features forfixing the implant body to a second bone portion. The implant body cancomprise a medical-grade thermoplastic or polymer. The implant body canhave an osteoconductive coating. To enhance the radiolucent property,the implant body may be coated with the osteoconductive coating at twoends of the implant body, leaving a middle region of the implant bodyuncoated.

Objects and advantages of embodiments of the disclosed subject matterwill become apparent from the following description when considered inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will hereinafter be described with reference to theaccompanying drawings, which have not necessarily been drawn to scale.Where applicable, some features may not be illustrated to assist in theillustration and description of underlying features. Throughout thefigures, like reference numerals denote like elements. As used herein,various embodiments can mean one, some, or all embodiments.

FIG. 1 is a perspective view of a titanium plasma coated medical gradethermoplastic or polymer proximal interphalangeal or distalinterphalangeal toe implant used for deformity correction of hammer toe,mallet toe or claw toe, according to one or more embodiments of thedisclosed subject matter.

FIG. 2 is a side view of the implant shown in FIG. 1, according to oneor more embodiments of the disclosed subject matter.

FIG. 3 is another side view of the implant shown in FIG. 1, according toone or more embodiments of the disclosed subject matter.

FIG. 4 is a proximal end view of the implant shown in FIG. 1, accordingto one or more embodiments of the disclosed subject matter.

FIG. 5 is a distal end view of the implant shown in FIG. 1, according toone or more embodiments of the disclosed subject matter.

FIG. 6 is a side view of an angled implant, according to one or moreembodiments of the disclosed subject matter.

FIG. 7 is a distal end view of the angled implant shown in FIG. 6,according to one or more embodiments of the disclosed subject matter.

FIG. 8 is a proximal end view of the angled implant shown in FIG. 6,according to one or more embodiments of the disclosed subject matter.

FIG. 9 is a bottom view of the angled implant shown in FIG. 6, accordingto one or more embodiments of the disclosed subject matter.

FIG. 10 is a cross sectional view of the angled implant shown in FIG. 6,according to one or more embodiments of the disclosed subject matter.

FIG. 11 is a side view of an implant, according to one or moreembodiments of the disclosed subject matter.

FIG. 12 is a distal end view of the implant shown in FIG. 11, accordingto one or more embodiments of the disclosed subject matter.

FIG. 13 is a proximal end view of the implant shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.

FIG. 14 is a partial distal end view of the implant shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.

FIG. 15 is a partial side view of the implant shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.

FIG. 16 is a partial side view of the implant shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.

FIG. 17A is a side view of an embodiment of an implant according to thedisclosed subject matter.

FIG. 17B is a cross-sectional view of an embodiment of an implantaccording to the disclosed subject matter.

FIG. 18A is a side view of an embodiment of an implant according to thedisclosed subject matter.

FIG. 18B is a cross-sectional view of an embodiment of an implantaccording to the disclosed subject matter.

FIG. 19 is a schematic view of an implant used to fuse two bonesaccording to the disclosed subject matter.

DETAILED DESCRIPTION

By the present disclosure there is provided a medical gradethermoplastic or polymer proximal interphalangeal or distalinterphalangeal toe implant having an osteoconductive coating. In someembodiments, the osteoconductive coating is titanium plasma and/orhydroxyapatite (HAp).

The present application includes examples showing how the presentinvention overcomes possible deficiencies and complications resultingfrom the use of conventional hammer toe, mallet toe or claw toe implantsmade out of K-wires, stainless steel, titanium, nitinol implants ornon-coated polymer implants.

For example, certain conventional implants for proximal interphalangeal(PIP) and distal interphalangeal (PIP) toe procedures studied by theapplicants have been focused merely on obtaining compression at thejoint to hold the joint together while waiting the 6-8 weeks untilfusion takes place. However, such implants may toggle and rotate (e.g.,if the joint interface is not the best bone), thus creating problems.Therefore, there is a need for a proximal interphalangeal or distalinterphalangeal toe implant that provides compression along with boneingrowth on the stems of the implant to help eliminate movement.

In one or more embodiments, a coated medical grade thermoplastic orpolymer proximal interphalangeal or distal interphalangeal toe implantused for deformity correction of hammer toe, mallet toe or claw toecomprises materials shown to be osteoconductive. Osteoconductivity isthe process by which bone grows on a surface (e.g., new bone growth thatis perpetuated by the native bone). The coated medical gradethermoplastic or polymer proximal interphalangeal or distalinterphalangeal toe implant may come in a variety of sizes depending onthe required deformity correction. In one or more embodiments, at leastone surface of the toe implant is coated with one or moreosteoconductive materials or compounds such as, for example, titaniumplasma and/or hydroxyapatite (HAp). Thus, a portion of the surface ofthe implant may remain uncoated, which can provide desirable attributesdescribed below.

In some embodiments, medical grade materials/polymers are used toreplicate bone as an implant. Medically accepted materials/polymersincluding but not limited to polyetheretherketone (PEEK),polyehterketoneketone (PEKK), Carbon Fiber-PEKK combination, titaniumplasma coated PEEK and other polymer composite material have passed thereview of the U.S. Food and Drug Administration (FDA), allowing them tobe used in medical implants. Some of these polymer composites have beenshown to be osteoconductive. In some embodiments, one or more surfacesare coated with an osteoconductive material or compound such as, forexample, HAp. Some such medical grade polymers have met the stringentmanufacturing guidelines ISO 10993 biocompatibility testing, along withother accepted manufacturing and biocompatibility guidelines. Medicalgrade polymers have the advantage of being able to be molded into anyshape or design desired, such as, for example, those shown in FIGS. 1-5,7-14, and 17-19 and discussed below.

Embodiments comprising an osteoconductive coating such as titaniumplasma and/or HAp have the advantage of providing an implant that offersosteoconductivity with ingrowth or upgrowth on the implant. In contrastto embodiments of the present disclosure, plain, non-coated PEEKimplants, for example, promote no bone upgrowth or ongrowth. However, animplant that retains at least a portion of the implant body uncoatedprovides improved radiolucent property of the implant, providing a viewof the bone edges that have been fused under fluoroscopy.

For purposes of promoting an understanding of the principles of thepresent disclosure, reference will now be made to the examplesillustrated in the drawings and described in the following writtenspecification. It is understood that no limitation to the scope of thepresent disclosure is thereby intended. It is further understood thatthe present disclosure includes any alteration and modifications to theillustrated examples and includes further applications of the principlesdisclosed herein as would normally occur to one skilled in the art towhich this disclosure pertains.

FIGS. 1-5 depict various views of embodiments of a titanium plasmacoated medical grade thermoplastic or polymer proximal interphalangealor distal interphalangeal toe implant used for deformity correction ofhammer toe, mallet toe and claw toe.

FIG. 1 is a perspective view of a titanium plasma coated medical gradethermoplastic or polymer proximal interphalangeal or distalinterphalangeal toe implant 100 used for deformity correction of hammertoe, mallet toe or claw toe, according to one or more embodiments of thedisclosed subject matter. Implant 100 comprises a threaded proximal endsection 102, a central section 106, and a distal end section 104.Threaded proximal end section 102 has threads for fixation to a firstbone portion and distal end section 104 has fixation features, such assplines, for fixing the implant 100 to a second bone portion.

Implant 100 comprises a medical-grade thermoplastic or polymer such as,for example, PEEK, and is coated with an osteoconductive coatingcomprising titanium plasma. In some embodiments, the coating is between125 microns and 500 microns thick. Alternatively or additionally, insome embodiments the osteoconductive coating comprises HAp.

In some embodiments, implant 100 includes one or more built-inconventional metal/alloy markers (not shown) located distally,proximally and/or in the middle of implant 100, to render the implantradiolucent. PEEK is translucent and the tantalum marker would allow itto be viewed under fluoroscopy. For example, markers can be included inimplant 100 at sections 102, 104, and/or 106. The markers can comprisetantalum metal/alloy or any other metal/alloy viewable underfluoroscopy. The middle section 106 can remain uncoated with titanium,further increasing radiolucency under fluoroscopy.

In some embodiments, implant 100 is not cannulated (i.e., it is solid).Alternatively, implant 100 can be cannulated as shown, for example, inFIGS. 4 and 5, and described below. In such embodiments, the cannuladiameter can be between 0.035 and 0.065 inches.

FIGS. 2 and 3 are side views of implant 100 shown in FIG. 1, accordingto one or more embodiments of the disclosed subject matter. As shown inFIGS. 2 and 3, implant 100 is straight. Alternatively, in someembodiments, implant 100 can be angled as shown, for example, in FIGS.6-10.

FIG. 4 is a proximal end view of implant 100 shown in FIG. 1, accordingto one or more embodiments of the disclosed subject matter. As discussedabove, implant 100 can be cannulated and include a proximal end cannulaopening 402.

FIG. 5 is a distal end view of implant 100 shown in FIG. 1, according toone or more embodiments of the disclosed subject matter. As discussedabove, implant 100 can be cannulated and include a distal end cannulaopening 502.

FIGS. 6-10 depict various views of an angled implant, according to oneor more embodiments of the disclosed subject matter.

FIG. 6 is a side view of an angled implant 600, according to one or moreembodiments of the disclosed subject matter. Implant 600 comprises athreaded proximal end section 602, a central section 606, and a distalend section 604. Threaded proximal end section 602 has threads forfixation to a first bone portion and distal end section 604 has fixationfeatures for fixing the implant 600 to a second bone portion. Centralsection 606 central is shaped such that threaded proximal end section602 is oriented at a predetermined angle to distal end section 604 ofthe implant 600.

As shown, implant 600 is 3.5 mm diameter×26 mm long with a 10°angulation. In other embodiments, implant 600 can be provided indifferent sizes/configurations depending on the specific anatomy anddesired correction. For example, the angulation can be between 0°(straight) and 25°.

Implant 600 comprises a medical-grade thermoplastic or polymer such as,for example, PEEK, and is coated with an osteoconductive coatingcomprising titanium plasma and/or hydroxyapatite (HAp). In someembodiments, the coating is between 125 microns and 500 microns thick.The osteoconductive (e.g., titanium plasma and/or HAp) coating promotesbone upgrowth on implant 600.

In some embodiments, implant 600 includes one or more built-inconventional metal/alloy markers (not shown) located distally,proximally and/or in the middle of implant 600, to render the implantradiolucent. PEEK is translucent and the tantalum marker allows it to beviewed under fluoroscopy. For example, markers can be included inimplant 600 at sections 602, 604, and/or 606. The markers can comprisetantalum metal/alloy or any other metal/alloy viewable underfluoroscopy.

In some embodiments, implant 600 is not cannulated (i.e., it is solid).Alternatively, implant 600 can be cannulated as shown, for example, inFIGS. 7, 8, and 10, and described below. In such embodiments, thecannula diameter can be between 0.035 and 0.065 inches.

FIG. 7 is a distal end view of angled implant 600 shown in FIG. 6,according to one or more embodiments of the disclosed subject matter. Asdiscussed above, implant 600 can be cannulated and include a distal endcannula opening 702.

FIG. 8 is a proximal end view of angled implant 600 shown in FIG. 6,according to one or more embodiments of the disclosed subject matter. Asdiscussed above, implant 600 can be cannulated and include a proximalend cannula opening 802.

FIG. 9 is a bottom view of angled implant 600 shown in FIG. 6, accordingto one or more embodiments of the disclosed subject matter. A crosssectional view of implant 600 at plane 902 is shown in FIG. 10.

FIG. 10 is a cross sectional view of angled implant 600 shown in FIG. 6,according to one or more embodiments of the disclosed subject matter. Asshown in FIG. 10, implant 600 is cannulated and includes a cannula 1002.In some embodiments, cannula 1002 can have a diameter between 0.035 and0.062 inches.

FIGS. 11-16 depict various views of a straight implant according to oneor more embodiments of the disclosed subject matter.

FIG. 11 is a side view of an implant according to one or moreembodiments of the disclosed subject matter. Implant 1100 comprises athreaded proximal end section 1102, a central section 1106, and a distalend section 1104. Threaded proximal end section 1102 has threads forfixation to a first bone portion and distal end section 1104 hasfixation features for fixing the implant 1100 to a second bone portion.

As shown, implant 1100 is 3.5 mm×22 mm, with a cannula diameter of 0.065inches. In other embodiments, implant 1100 can be provided in differentsizes/configurations depending on the specific anatomy and desiredcorrection. For example, the cannula diameter can be between 0.035 and0.065 inches.

Implant 1100 comprises a medical-grade thermoplastic or polymer such asPEEK, and is coated with an osteoconductive coating comprising titaniumplasma and/or hydroxyapatite (HAp). In some embodiments, the coating isbetween 125 microns and 500 microns thick.

In some embodiments, implant 1100 includes one or more conventionalbuilt-in metal/alloy markers (not shown) located distally, proximallyand/or in the middle of implant 1100, to render it radiolucent. PEEK istranslucent and the tantalum marker allows it to be viewed underfluoroscopy. For example, markers can be included in implant 1100 atsections 1102, 1104, and/or 1106. The markers can comprise tantalummetal/alloy or any other metal/alloy viewable under fluoroscopy.

In some embodiments, implant 1100 is not cannulated (i.e., solid).

FIG. 12 is a distal end view of implant 1100 shown in FIG. 11, accordingto one or more embodiments of the disclosed subject matter. As discussedabove, implant 1100 can be cannulated and include a distal end cannulaopening 1202, as shown in FIG. 12.

FIG. 13 is a proximal end view of implant 1100 shown in FIG. 11,according to one or more embodiments of the disclosed subject matter. Asdiscussed above, implant 1100 can be cannulated and include a proximalend cannula opening 1202, as shown in FIG. 13.

FIG. 14 is a partial distal end view of implant 1100 shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.Distal end section 1104 includes fixation features 1402 for fixing theimplant 1100 to a portion of bone.

FIG. 15 is a partial side view of implant 1100 shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.Threaded proximal end section 1102 includes threads 1502 for fixation toa portion of bone.

FIG. 16 is a partial side view of implant 1100 shown in FIG. 11,according to one or more embodiments of the disclosed subject matter.Distal end section 1104 includes fixation features 1602 for fixing theimplant 1100 to a portion of bone.

FIGS. 17A and 17B illustrate a view of another embodiment of theimplant. These figures include dimensions in millimeters and degreesshowing a particular embodiment, however, the disclosed subject matterincludes embodiments with dimensions that differ from those shown andthus, the disclosed subject matter as a whole is not limited to thespecific dimensions shown.

The implant 1700 has a hollow body (the central cavity 173 shown in FIG.17B) with three sections. The distal section 174 has three barbs ofincreasing size, as shown in FIGS. 17A and 17B. The first barb 1701 hasthe lowest rise from the central cavity, the second barb 1702 has ahigher rise, and the third barb 1703 has the highest rise. The rise canbe characterized as the outermost diameter of the barb. In alternativeembodiments, the barbs can differ in terms of number, the arrangementsof the rises. In embodiments, the rises of two or more barbs can beequal. For example, the first rise 1701 can be smaller while the othertwo 1702 and 103 can be larger and identical in outer diameter. In anembodiment, the outermost diameter of the first barb is 3.6 mm (with atolerance of +/−0.05 mm); the outermost diameter of the second barb is3.8 mm (with the same tolerance); and the diameter of the third barb is3.9 mm (with the same tolerance).

The progressive increasing (or ramping) of the barb outer diameter hasshown advantages when the implant is inserted into a bone cavity. Bonesobserved before and after insertion of the implant have shown lessdamage to marrow and internal bone structure with the disclosedincreasing barb diameter as compared to an implant with uniformly sizedbarbs. When a barb is pressed against the outer wall of the bone cavity,it compresses the internal material and structure in the bone. Thecompression occurs incrementally as each barb passes through the bonecavity, thereby compressing the side wall of the bone cavity in stages.Further, the disclosed arrangement of barbs shows increased retentionstrength as compared to uniformly sized barbs. The tissue in the bonecavity is only compressed to a maximum extent once, and thus recoversmore fully to its original size and position to retain the barb.

This concept applies to embodiments with more or less than three barbs,such as the embodiment of FIG. 6. Thus, an implant with any number ofbarbs which are arranged with outer diameters increasing from the distalend of the implant toward the central region is contemplated by thepresent disclosure.

Referring to FIG. 17B, the proximal portion 172 of the implant 1700includes a dual-tapered portion. The first taper 175 extends from theproximal end of the proximal portion for 2 mm in an embodiment. Then,the second taper 177 continues for 8.75 mm. The first taper 175 may forman angle of 70 degrees from vertical, as shown in FIG. 17B. Although nothreads are shown on proximal portion 172, in embodiments threads 182may be present, as shown in FIGS. 18A-B. As shown in FIGS. 17B and 18B,embodiments of implant 1700 include a monolithic body.

Referring to FIG. 18A, threads 182 are formed on the proximal portion172. The threads 182 extend radial away from a tubular section 183 andhave an outer diameter that increases progressively from the proximalend toward the central portion 176. Thus, the outermost diameter of theproximal portion 172 (formed by the outermost surface of threads 182)increases from the proximal end toward the central portion 176. Thisprogressive increase in the outer diameter of the threads providesadvantages as noted above with respect to the barbs 1701, 1702, and1703. As seen in FIG. 18A and in the cross-section view in FIG. 18B, thecentral portion 176 does not have any attachment features and has asmooth, cylindrical, outer surface that extends continuously from theproximal portion 172 to the distal portion 174.

In an embodiment, the tubular section 183 has an outer diameter that isconstant, rather than increasing progressively like the threads 182. Inanother embodiment, the tubular section 183 is itself tapered and itsouter diameter increases progressively from the proximal end toward thecentral portion 176.

In an embodiment, the entirety of the external surface of implant 1700is coated with a osteoconductive coating. As noted above, a portion ofthe implant 1700 may remain uncoated to provide improved radiolucencyunder fluoroscopy. In an embodiment, the central portion 176 is notcoated, while portions 172 and 174 are coated. Of course, this coatingarrangement also applies to FIGS. 18A-B, where portions 174 and threadedportion 182 can be coated, while the central portion 176 remainsuncoated. In an embodiment, the central portion 176 is coated with anosteoconductive coating that is radiolucent while the rest of theimplant is coated with a coating that is less radiolucent. In someembodiments, the entirety of the implant is coated with anosteoconductive coating that is radiolucent, thus making the coatedimplant radiolucent.

By leaving the central portion 176 uncoated, the radiolucency of theimplant is increased in the region where the two bones being fused areexpected to come together, while the distal portion and the proximalportion, coated with the osteoconductive coating, provide a compatiblesurface for bone growth. The improved radiolucency enables the clinicianto observe the bone edges 191 and 192 under fluoroscopy during theprocedure and/or at the conclusion, to ensure that the edges are incontact or at a position suitable for fusion of the two bone edges, asshown in FIG. 19.

FIG. 19 represents a schematic of a fluoroscopy view that a clinicianwould observe when the central portion 176 is uncoated, while portions172 and 174 are coated with an osteoconductive coating that impedesradiolucency. The improved radiolucency of the central portion 176enables the clinician to monitor the fusion of the two bone edges overtime, such as after 4-6 weeks, to observe and verify whether bone fusionis taking place. Because the region of interest where the bones aresupposed to be fusing is not obscured by the implant, due to itsradiolucency, it is typically possible to verify bone growth with asingle fluoroscopic view. Conversely, an implant that is not radiolucentcan obscure the bone fusion, making it more difficult for the clinicianto ascertain the patient's progress.

A method of using an implant according to one or more embodiments of thedisclosed subject matter will now be described.

Initially, the surgeon makes an incision over the dorsal aspect of thedistal interphalangeal joint (DIP) or proximal interphalangeal joint(PIP) of the toes. Standard soft tissue releases are performed asnecessary. The joint dissection and access should provide completevisualization of the articular surfaces of the middle and proximalphalanges of the DIP or PIP joints. The surgeon then prepares the jointsurface of both the proximal and middle phalanges.

When using a solid implant (i.e., an implant without cannulation), thesurgeon drills with the appropriate size drill bit, both sides of theDIP or PIP joints to the required depth. Surgeon then taps, ifdesirable, with the appropriate size tap both sides of the DIP or PIPjoint to the required depth. Once both sides of the DIP or PIP jointsare prepared properly, the surgeon then inserts the proximal portion ofthe implant into the proximal side of the joint either by hand or withthe recommended instrument, to the recommended depth. Surgeon thendistracts the joint distally, to pressfit the distal end of the implantinto the predrilled/tapped hole of the DIP or PIP joint.

When using cannulated implants, after preparing the joint surface, thesurgeon places a guide wire (e.g., from 0.035 up to 0.062 inches indiameter) into the proximal phalanx along its central axis, to therecommended depth. The surgeon then verifies proper positioning of theguide wire with AP (Anterior/Posterior) and Lateral (Medial/Lateral)fluoroscopic views. The surgeon then uses the recommended cannulateddrill bit to predrill over the guide wire to the recommended depth. Thesurgeon then taps the drilled hole, if desirable, with the appropriatesize tap to the recommended depth. The surgeon then removes the guidewire proximally to perform the same procedure to prepare the distal sideof the joint.

The cannulated implant is then placed over the guide wire still inposition distally. The surgeon, either by hand or with the recommendedinstrument, advances the cannulated implant over the guide wire intoposition in the distal end of the joint to the recommended position.

The guide wire is then advanced forward antegrade out the end of thetoe, under the toe nail, so that its proximal end is flush with theimplant. The surgeon then distracts the DIP or PIP joint in order toinsert the proximal portion of the implant into the prepared jointproximally. The implant is pressfit or placed into the proximal portionof the joint to the recommended position.

The surgeon may remove the guide wire or advance the guide wire backthrough the cannulated implant past the DIP or PIP joint, to addressfixation at the metatarsophalangeal (MTP) joint of the toe.

Embodiments of the present disclosure can be used for primary/revisionof claw toe, hammer toe, or mallet toe deformity. Embodiments can beused for angular correction of deformities, arthritic conditions oflesser toes (traumatic/rheumatologic), and/or salvage of failed priorsurgeries to lesser toes.

In the embodiments shown and described, a coated medical gradethermoplastic or polymer proximal interphalangeal or distalinterphalangeal toe implant can be coated with a titanium plasma and/orhydroxyapatite (HAp) osteoconductive coating, can be provided in varioussizes, cannulated or solid, angled or straight, with or withoutfluoroscopy markers, depending on the amount of correction required toaddress the deformity.

Although some embodiments herein have been described with respect totitanium plasma coated implants, embodiments of the disclosed subjectmatter are not limited thereto. Rather, embodiments can include implantscoated with other osteoconductive coatings such as HAp.

In this application, unless specifically stated otherwise, the use ofthe singular includes the plural and the use of “or” means “and/or.”Furthermore, use of the terms “including” or “having,” as well as otherforms, such as “includes,” “included,” “has,” or “had” is not limiting.Any range described herein will be understood to include the endpointsand all values between the endpoints.

Features of the disclosed embodiments may be combined, rearranged,omitted, etc., within the scope of the invention to produce additionalembodiments. Furthermore, certain features may sometimes be used toadvantage without a corresponding use of other features.

It is, thus, apparent that there is provided, in accordance with thepresent disclosure, titanium plasma coated medical grade thermoplasticor polymer proximal and distal interphalangeal toe implant. Manyalternatives, modifications, and variations are enabled by the presentdisclosure. While specific embodiments have been shown and described indetail to illustrate the application of the principles of the invention,it will be understood that the invention may be embodied otherwisewithout departing from such principles. Accordingly, Applicant intendsto embrace all such alternatives, modifications, equivalents, andvariations that are within the spirit and scope of the presentinvention.

The invention claimed is:
 1. A toe implant for deformity correction of ahammer toe, a mallet toe, a claw toe, or an arthritic toe condition, thetoe implant comprising: a monolithic body constructed frompolyetheretherketone, the monolithic body including a proximal endsection at a proximal end of the toe implant for fixation to a firstbone portion, the proximal end section being tapered at the proximal endto aid insertion of the proximal end section into the first boneportion, a distal end section at a distal end of the toe implant forfixing the monolithic body to a second bone portion, the distal endsection being tapered at the distal end to aid insertion of the distalend section into the second bone portion, and a central portion rigidlyconnecting the proximal end section and the distal end section; and anosteoconductive coating on the proximal end section and the distal endsection, wherein the osteoconductive coating provides a surface forpromoting bone growth when the toe implant is implanted in the firstbone portion and the second bone portion, and the central portion of themonolithic body does not have any osteoconductive coating applied, suchthat the central portion is radiolucent after the osteoconductivecoating is applied to the proximal end section and the distal endsection.
 2. The toe implant of claim 1, wherein the osteoconductivecoating comprises titanium.
 3. The toe implant of claim 1, wherein themonolithic body is not cannulated.
 4. The toe implant of claim 1,wherein the monolithic body is cannulated.
 5. The toe implant of claim1, wherein the central portion has a shape that causes the proximal endsection of the monolithic body to be rigidly oriented at a predeterminedangle to the distal end section of the monolithic body.
 6. The toeimplant of claim 5, wherein the predetermined angle is a non-zero anglefor performing an angular correction of a deformity of a toe.
 7. The toeimplant according to claim 1, wherein the central portion includes acylindrical outer surface that extends continuously from the proximalend section to the distal end section.
 8. The toe implant according toclaim 1, wherein the distal end section includes a plurality of barbs,each having a respective outer diameter, and the respective outerdiameters of the plurality of barbs increase from the distal end of thetoe implant toward the proximal end of the toe implant.
 9. The toeimplant according to claim 8, wherein the proximal end section includesthreads, and the outer diameter of the threads increases from theproximal end of the toe implant toward the central portion.
 10. The toeimplant according to claim 1, wherein the distal end section includes aplurality of barbs, each having a respective outer diameter, therespective outer diameters of the plurality of barbs increase from thedistal end of the toe implant toward the proximal end of the toeimplant, and the proximal end section includes a plurality of threads.11. The toe implant according to claim 1, wherein the proximal endsection is tapered at two different angles.
 12. A toe implant fordeformity correction of a hammer toe, a mallet toe, a claw toe, or anarthritic toe condition, the toe implant comprising: a monolithic bodymade of polyetheretherketone, including a proximal end section, at aproximal end of the toe implant, for fixing the monolithic body to afirst bone portion, a distal end section, at a distal end of the toeimplant, for fixing the monolithic body to a second bone portion, and acentral portion rigidly connecting the proximal end section and thedistal end section; and a layer of titanium coated on the proximal endsection and on the distal end section, wherein the layer of titaniumprovides a surface for promoting bone growth when the toe implant isimplanted in the first and second bone portions, and the central portionof the monolithic body does not have any titanium coating applied, suchthat the central portion is radiolucent after the layer of titanium isapplied to the proximal end section and the distal end section.
 13. Thetoe implant of claim 12, wherein the layer of titanium comprisestitanium plasma.
 14. The toe implant of claim 12, wherein the distal endsection includes a plurality of barbs, each having a respective outerdiameter, the respective outer diameters of the plurality of barbsincrease from the distal end of the toe implant toward the proximal endof the toe implant, and the proximal end section includes a first taperat the proximal end of the toe implant extending for a first distanceand a second taper extending from an end of the first taper.
 15. The toeimplant of claim 14, wherein the proximal end section includes threads,and the outer diameter of the threads increases from the proximal end ofthe toe implant toward the central portion.
 16. The toe implant of claim12, wherein the central portion is shaped such that the proximal endsection of the monolithic body is oriented at a predetermined non-zeroangle to the distal end section of the monolithic body.
 17. The toeimplant according to claim 12, wherein the central portion includes acylindrical outer surface that extends continuously from the proximalend section to the distal end section.